Telephone system



A. E. LUNDELL AND E. H. CLARK.

TELEPHONE SYSTEM.

APPLICATION FILED DEC. 10. 1917.

1,362,020. atented Dec. 14, 1920.

H mm I III/II .52 /e (for A/be/v ELM/Me fa ar/lC/ark y Am A. E. LUNDELLAND E. H. CLARK. TELEPHONE SYSTEM.

APPLICATIOQ FILED 0Ec.1o, I9l7.

Patented Dec. 14, 1920.

4 SHEETS-SHEET 2- A. LUNDELL AND E. H. CLARK.

TELEPHONE SYSTEM.

APPLICATION FILED DEC. 10, 1917.

A/be/v f. ZI/IMJ/Z/ fayar h C/ar/r Kww A. E. LUNDELL AND E. H. CLARK.

TELEPHONE SYSTEM.

APPLICATION FILED DEC.10,1917.

Patented Dec. 14, 1920 4 SHEETS-SHEET 4.

M ken 70/5: 14/507 5 Lana z L dffif H C/am? UNITED STATES PATENT OFFICE.

ALBEN E. LUNDELL AND EDGAR H. CLARK, OF NEVJ YORK, N. Y., ASSIGNORS TO VIESTERN ELECTRIC COIIEPANY, INCORFOIR-ATED, 0E NEVI YORK, N. Y., A COR- PORATION OF NEW YORK.

TELEPHONE SYSTEM.

Application filed. December 10, 1917.

To all whom, it may concern:

Be it known that we, ALnnN E. LUNDELL and EDGAR H. CLARK, citizens of the United States, residing at New York, in the county 01 Bronx and State of New York, and at New York, in the county of New York and State of New York, respectively, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone systems and more particularly to telephone systems employing automatic switches.

in telephone systems in which an operator is employed to control the setting of a plurality of automatic switches for completing a connection bet-ween a calling and a called party, it is customary to provide a plurality of selectively adjustable sending devices and also means for associating an idle sending device with the cord circuit employed by the operator to establish connection to. the calling substation. It was formerly the practice to provide a set of controlling relays for each of the sending devices employed.

In accordance with the present invention, it is proposed to provide a single set of controlling relays for a plurality of sending devices and further to provide means to associate a set of controlling relays with a sending device which is allotted or taken for use.

In the present embodiment of the invenoach operator is provided with a plurality of connecting link circuits. Each one of these link circuits has an associated sequence switch individual thereto. A. controlling key set is provic ed at each operators position. A plurality of register senders are also provided at each position and are commonly available for use in connection with any link circuit. Associated with each register sender is a cord finder which controls the connection or register sender with a link circuit which has been taken for use. The cord finder which is to be put into operation at any given time is determined by the action of an allotter switch which prepares an idle cord finder to? operation at the proper time.

Briefly. the operation of the system is as follows. When an operator responds to a Specification of Letters Patent.

Patented Dec. 14, 1920.

Serial No. 206,428.

manual call by means oi the plug end of her link circuit, the associated sequence switch is moved out or" its normal position. It thereupon sets up a condition to move the sequence switch associated with an allotter cord finder out ct its normal position, it l)O-- mg borne in mind that only the sequence switch which is associated with the allotted cord finder can be in its normal position. The movement or" the sequence switch associated with the connecting link circuit also serves to place a characteristic test potential on the multiple terminals assigned to such link circuit in the multiple contact bank served by the various cord finders. As soon as the cord finder has found the desired link circuit, the register sender is connected to the link circuit.

The registers are positioned under the con rol of the operators key set and operate in a hunting movement under the control of test relays.

l he drawings, when taken together, diagrammatically represent a portion of a tele phone system. Figure 1 represents a calling subscribers line, an answering cord and an automatic switch or district selector for extending the answering cord to a distant station; 2 diagrammatically represents a cord finder or switch for associating an allotted sending device with the cord circuit taken for use. In the lower right-han d corner of Fig. 2 there is shown the well known series of counting relays forming a part of one sending device; Figs. 3 and 4E diagrammatically represent the selectively operable switches or registers and controlling circuits of two sending devices, the registers shown above the dotted line in Fig. l being related to one sending device, while the registers shown below the dotted line form part of a second sending device. In the upper left-hand corner of Fig. 3 there is shown an allotter for ,allotting or associating an idle cord finder and its sending device with the cord circuit taken for use.

in this system there is shown a plurality of automatic selector switches, each of which is of a type shown in the patent to Craft and Reynolds, No. 1,123,696. January 5, 1.915. The circuits for the switches are shown in the patent to Lundell,No. 1,168,319, January 18, 1916. The registers, key sets and counting relay arrangements comprising the sending devices, are more fully disclosed in the above mentioned patent to Lundell.

The sequence switches and registers, employed in the system employed in this disclosure, are of the type shown in the patent to Reynolds and Baldwin, No. 1,127,808, February 9, 1915 and are similar in operation and function to the sequence switches disclosed in the patent to McBerty, No. 1,125,579, January 19, 1915.

It is believed that the invention can best be understood by describing the manner of initiating a call. When the subscriber at A removes his receiver from its switchhook, the line relay 101 is energized in the wellknown manner to light a lamp signal 102. The operator, on noting this signal, inserts the answering plug 103 into the jack 104 of the calling line, and thereupon depresses her listening key 105 to associate her head set, generally designated 106, with the calling line to ascertain the number of the desired line. As soon as the plug 103 is inserted into the jack 104, the cut-oif relay 107 and relay 108 are energized over a circuit extending from grounded battery, winding of relay 107, sleeve of the ack 104, sleeve of the plug 103, winding of relay 108 to ground. The cut-off relay 107 on energizing disconmerits the line relay 101 from the calling line, which relay on deenergization extinguishes the line signal 102. The relay 108, when energized in the above described circuit, attracts its armature to complete a circuit from ground through armature and front contact of relay 108, contact 109, winding of the power magnet of sequence switch 100 to grounded battery, to move the sequence switch into position 2.

In the present system an allotter 300 is employed, the operation of which will be more fully described hereinafter. The allotter in its various positions assigns for use an idle cord finder with its associated sending device. For purposes of this description, it will be assumed that the allotter 300 is in position 0, with the result that the cord finder switch CF of Fig. 2 and the registers 400, 401. 402, 403 and 404 are effective.

lVith the sequence switch 100 in position 2, a circuit is closed from ground through contact 110, conductor 111, contact 201, winding of the power magnet of the cord finder sequence switch 200 to grounded battery, to move this sequence switch into position 2. As soon as the cord finder sequence switch reaches position 2, an energizing circuit is completed for the up-drive magnet 202, from grounded battery through contact 203, left hand back contact and armature of relay 204 to ground. Under the control of the updrive magnet 202, the cord finder, generally designated CF, elevates its brushes over the groups of terminals which are connected to the operators cord circuits. When the brushes of the'cord finder are in engagement with the terminals representing the cord which is connected to the calling line, the relay 204 is energized to stop the upward movement of the cord finder. The energizing circuit of the relay 204 is traceable from grounded battery, winding of relay 204, contact 205, brush 206, terminal 207, conductor 208, contact 112 to ground. The relay 204 attracts its armatures and at its left-hand bark contact and armature interrupts the energizing circuit of the up-drive magnet 202 and at its right-hand armature and front contact completes a locking circuit for itself under the control of this circuit; relay 204 is maintained energized until the cord finder sequence switch moves out of position 16. This locking circuit may be traced from grounded battery, winding of relay 204, contact 209, right-hand armature and front contact of relay 204, brush 210, terminal 211, conductor 212, contact 113 to ground. As soon as the relay 204 attracts its left-hand armature, a circuit is closed for moving the cord finder sequence switch 200 out of position 2 into position 3. The energizing circuit for this sequence switch extends from grounded battery, winding of the power magnet of sequence switch 200, contact 213, left-hand front contact and armature 204 to ground.

After the operator has ascertained the number of the desired line, she depresses the numeral keys in accordance with this number and also the start key 301 to energize the start relay 302. With relay 302 energized and with a numeral key in each of the columns of keys depressed, energizing circuits are completed for setting the registers 400 to 404, inclusive. The energizing circuit for the register 400 may be traced from grounded battery, contact 215, conductor 216, power magnet of register 400, conductor 405, lefthand armature and back contact of stop re lay 308, conductor 309, to ground at the left-hand armature and contact of start relay 302.

Under the control of this energizing circuit, the register 400 continues to rotate until it reaches the stop position indicated by the key depressed. If it be assumed that the district key 310 is depressed, when the register 400 reaches position 8, an energizing circuit for the stop relay 308 will be completed from grounded battery, winding of this relay, contact 312, conductor 311, contact 406, conductor 407, key 310, conductor 313, con tact 314, winding of relay 315, conductor 316, contact 217, to ground. The energization of the stop relay 308 interrupts the driving circuit of register 400. Similarly, the register 401 is set over an energizing circuit cor-- pleted from battery over conductor 52 winding of the power magnet of register 401, conductor 408, left-hand armature and contact of relay 317, conductor 309, to ground at the armature and contact of relay 302. When the register 401 is set to the position indicated by the depressed key 318, the stop magnet 317 is energized over a circuit similar to that described for the stop relay 308. Therelay 31'? on energization at its left-hand armature opens the operating circuit of the register 401. At the same time the registers 402, 403 and 404 start rotating and in a manner similar to the operation of the stop relays 308 and 317, the stop relays 319, 320 and 321 are actuated to stop their respective registers in the desired positions in accordance with the depression of the hundreds, tens and units keys, respectively. As soon as all the registers have been set, the cord finder sequence switch 200 is moved out of position 3 and into position 4, by a circuit ere tending from grounded battery, winding 01 the power magnet of sequence switch 200, contact 213, conductor 214, through the right-hand contacts and armatures of all the stop relays 308, 317, 319, 320 and321, to ground at the armature and contact of the relay 302.

In position 4 of sequence switch 200, a circuit is closed from grounded battery, contact 250, conductor 340 and in parallel through key releasing rel: ys 303, 304, 305, 30-6 and 30?. to ground. T he keys are released and thereby interrupt the energizing circuit of relay 315. The cord finder sequence switch 200 is now moved out of position 4 and into position 5 by a circuit traceable from grounded battery, winding of the power magnet of the sequence switch 200, contact 218, conductor 219, contact 322, left-hand back contact of relay 315 to ground.

WVith the district sequence switch 100 in position 2 and the cord finder sequence switch 200 in position 5, line relay 114 is energized over a fundamental circuit 6X- tending from grounded battery, winding of relay 114, contact 115, conductor 116, terminal 220, brush 221, conductor 223, outer armature and back contact or" the upper zero counting relay 224, windings of the stepping relay 225, contact 226, brush 227, terminal 228, conductor 229, contact 117 to ground. The line relay 114 is energized and attracts its armatures, and at its lefthand front contact and armature establishes a locking circuit for itself through contact 118 and then over the circuit just described, to ground. At the right-hand armature and front contact of relay 114 a circuit is closed from ground through contact 119, conductor 120, winding of the power magnet oi sequence switch 100, to grounded battery, to move the sequence switch into position 3. In position 3, with the relay 114 still energized, the up-drive magnet 121 has its energizing circuit completed from grounded battery,

Winding of this magnet, contact 122, righthand front contact and armature or" relay 114 to ground. switches of one hundred point tyie are used. lVith this assumption, under the cor.- trol of the Lip-drive magnet 121, the district selector switch generally designated 123, elevates its brushes over the terminals of the group of trunks leading to other selector switches. As the selector 123 is elevated, its commutator brush 124 successively engages conducting segments of the commutator 125. Each time that the commutator brush engages a conducting segment, the stepping relay 225 is shunted. This shunting circuit may be traced from grounded battery, winding of relay 114, left-hand contact and armature of relay 114, contacts 118 and 126, a conducting segment of the commutator 125, commutator brush 124 to ground. For each shunting operation of the stepping magnet one of the series of counting relays is actuated and locked up. This shunting operation continues until the upper zero counting relay 224 attracts its armatures. At the outer armature of: this relay, the fundamental circuit is opened, and at its inner armature, a circuit is closed from ground through conductor 230, contact 231, winding of the power 'magnet ot the sequence switch 200, to grounded battery, to move the sequence switch out of position 5 and into position As soon as the fundamental circuit interrupted, the line relay 114 deenergizes and at its right-hand front contact opens the circuit of the n p-drive magnet 121 to stop the movement of the selector switch 123. At the right-hand back contact and armature of relay 114, a circuit is closed to more sequence switch 100 into position 11.

After the setting of the district selector switch 123 in operative relation to a selected group, it will be understood that thereafter the switch will hunt for an idle trunk lea (ling to a succeeding selector switch (not shoi n). T he brush tripping mechanism, as well as the arrangement for causing the district selector to trunk hunt have not vbeen shown, since they are well-known in the art and form no part of this invention.

In position 7 of the cord finder sequence switch 200, the actuating circuit for the counting relays is completed through the contact of the register 401 which was closed when this register was set. hen the selecting operation controlled by the register 401 is completed, the upperzero counting relay 224 is again actuated to open the tundamental circuit and to move the cord finder sequence switch 200 into position 11, in which a third selecting operation is completed. Other selecting operations are successively controlled in accordance with the setting oi the registers 402, 403 and 404. After each of these selecting operations, the

It has been assumed that sequence switch 200 is moved successively into positions 13, 15 and 16. As soonas the cord finder sequence switch reaches position 16, the district sequence switch 100 is moved out of position 11 and into position 16, or its talking position. This circuit extends from grounded battery, power magnet of sequence switch 100, contact 126, conductor 127, ter minal 232, brush 233, contact 234, to ground. When the sequence switch 100 moves out of position 11, the holding circuit for the relay 204 is interrupted at the contact 113. The

relay 204 deenergizes and at its left-hand backcontact and armature completes a cir-.

cuit from ground through contact 235 through the power magnet of the sequence switch 200 to grounded battery, to move this sequence switch into position 17. In position 17, the cord finder is restored to its normal position under the control of the clowndrive magnet 236. The circuit for thismagnet is completed through contact 237. As soon as the cord finder reaches its normal position, a. circuit is closed from ground through commutator brush 238, normalsegment 239 of the commutator, contact 240, winding of power magnet of sequence switch 200, to grounded battery. Under the control of this circuit, sequence switch 200 moves into position 18, in whichposition it remains until the cord finder and its related sending device are allotted for use by the allotter 300. g

It will be understood in practice that a plurality of cord finders with an associated sending device are used. In order that an idle cord finder and sending device may be associated with the cord circuit taken for use, an allotter is employed. This allotter is shown in the upper portion of Fig. 3 and may be of the well-known sequence switch structure. The operation of the allotter is as follows. As soon asthe cord finder sequence switch reaches position 5 and in all positions from 5 to 17 inclusive, a circuit is completed for moving the allotter 300 out of the position in which it was then at rest. Under the assumption of the present case, it is assumed that the allotter is standing in position 6, in which casea circuit is closed from ground, contact 324, conductor 325,

contact 241, conductor 242, winding of the power magnet of allotter 300, to grounded battery, to move the allotter into position 7. If a cord finder and sending device assigned in position 12, are now available for use, its cord finder sequence switch, similar to the one shown at 200 in Fig. 2, will be standing in position 18. Under these conditions, a circuit will be closed for the allotter 300 from grounded battery, through the windingof this power magnet, contact 326. conductor 327, contact 243, to ground. Under the. controlof this circuit the allotter will move into position 12, at which time the contacts 328, 329, 330, 331 and 332, extend the controlling circuits of the stop relays 308, 317, 319, 320 and 321, respectively, to the registers of the second sending device (not shown.) As soon as the allotter 300 stops in position 12, the cord finder sequence switch of the allotted cord finder, shown in the dotted rectangle at the right of Fig. 2, will be moved into position 1 over a circuit extending from ground, contact 246, conductor 245, through the sequence switch contact closed in position 18, of the cord finder sequence switch (not shown) but similar in operation to the sequence switch 200. Under the control of this last described circuit, the sequence. switch of the allotted cord finder is moved from position 18 into position 1.

If this second sending device is busy, its cord finder sequence switch will be in some position between 5 and 17, in which position the allotter will be -moved into position 13 over a circuit extending from grounded battery, winding of the power magnet of sequence switch 300, conductor 242, contact 244, conductor 245, contact 246, to ground. If the other cord finder is idle, in which case its sequence switch will be moved in position 18, the allotter will be moved into position 1 over a circuit traceable from grounded battery, winding of the power magnet of allotter 300, contact 326, conductor 327, through a contact similar to 243 to ground. In position 1 of the allotter, the sending device whose registers are indicated below the dotted line in Fig. 4, will become effective.

' In case all the sending devices are in use no one of the cord finder sequence switches will be in position 18. As a result of this, the allotter will remain in position 2, 7 or 13 as long as all of the sending devices are in use. The relay 315 will then be energized over a circuit closed from grounded battery, through resistance 336, contact 337, winding of relay 315, contact 338, to ground. The relay 315 attracts its armatures and at its right-hand armature and contact completes a circuit from grounded battery, through contact 339,0onductor 340, through the key releasing magnets 303 to 30'? inclusive, in parallel to ground. As long as the relay 315 remains energized, the key release magnets are energizedand-it will be impossible to lock the keys in depressed position as long as all of the sending devices are in use. When, however, one of the cord finder sequence switches moves into position 18, the battery for energizing the relay 315 is shunted by ground applied over conductor 342, through a contact similar to contact 343, to ground.

It will thus be seen that in this system, a single set of controlling relays has been provided for a plurality of sending devices and that means are also provided to associate the set of controlling relays with a sending device which is allotted for use.

What is claimedis:

In a telephone system, a plurality of sets of mechanical sending devices, a set of relays for controlling the setting of said sending devices, and means for selectively associating said set of controlling relays with any one of said sets of sending devices.

2. In a telephone system, a plurality of sending devices each comprising a mechanical switch, means for alloting an idle sending device, a relay for controlling the extent of movement of said sending devices, and means for associating said controlling relay with an allotted sending device.

3. In a telephone system, sets of selectively operable switching devices each set operating as a sender, a set or relays for controlling the extent of movement of said switching devices, and means for successively associating said set of controlling relays with an idle set of switching devices.

4. In a telephone system, a plurality of multi-position switches each operating as an impulse sending device, a relay controlling the extent of movement of said switches, and means for associating said relay with any one of said switches.

5. In a telephone system, a plurality of mechanical impulse transmitting devices, a relay for controlling the extent of movement of said devices, and means for associating said relay with any one of said devices.

G. In a telephone system, a plurality of point finders having fixed contacts, means for electrically distinguishing said contacts, common means for determining the stopping point of said point finders in accordance with the electrical conditionot said contacts, and mechanism for associating said means with an idle point finder.

7. In a telephone system, a plurality of sets of point finders each point finder having fixed contacts arranged to be electrically distinguished, common means for determining the stopping points of the finders of any set depending on the electrical condition of said contacts, and mechanism for associating said common means with an idle set or" point finders.

8. In a telephone system, a plurality of mechanical register senders, common electrical means for controlling the setting of said senders, and means for selectively associating said controlling means with an idle register sender.

9. In a telephone system, a plurality of switches, trunks associated therewith, a plurality of mechanical register senders for controlling said switches over said trunks, electrical means common to said senders for controlling the setting thereot, means for allotting a sender and controlling means for use,

and means for connecting the allotted sender to a trunk taken for use.

10. In a telephone system, a set of digits keys, a plurality of registers, means common to said registers and operating under the control of said digits keys for stopping any register, and an allot-tor for associating a register and the common stopping means with said set of digits keys.

11. In a telephone system, a plurality of impulse counting devices, each comprising a series of counting relays, a mechanical de vice associated with each series of counting relays for determining the number of relays to be efiected in any operation, electrical means common to all of said devices for controlling the operation thereof, and mechanism for associating said controlling means with any device taken for use.

12. In a telephone system, a plurality of selector switches, trunks associated therewith, a plurality of senders for transmitting impulses over said trunks to control the setting of said selectors, a single set of digits keys for controlling the setting of said senders, each of said senders comprising sequence switch registers and a series of counting relays, an allotter for allotting senders for use, and means common to all of said senders and operating under the control of said set of keys for determining the setting of the registers, said means being associated by said a-llotter with any sender taken for use.

13. In a telephone system, a plurality of point finders each point finder comprising a series of fixed elements and a movable element cooperating therewith, means for characterizing any desired fixed terminal by a distinguishing electric condition, means for operating said movable elements, stopping means common to said point finders for stopping the movable element of any point finder in engagement with an electrically distinguished fixed element of the same point finder and mechanism for associating said stopping means with an idle point finder.

l-l. In a telephone system, a plurality of point finders each point finder comprising a series of fixed elements serving as terminals of electrical conductors, a movable element serving a terminal of an electrical con ductor cooperating therewith, means for characterizing any desired fixed terminal by a distinguishing electrical condition over its conductor, means for operating said movable elements, sto oping means common to said point finders for stopping said movable elements, and a circuit for controllin said stopping means completed over said movable element and said electrically distinguished fixed element, and mechanism for associating said stopping means with an idle point finder.

15.7 In a telephone system a plurality of point finders each point finder having a series of fixed elements and a movable element cooperating therewith, said fixed elements serving as terminals of electrical conductors over which said elements may be distinguished, said conductors being provided with manually controlled means whereby said fixed elements may be char acterized by a distinguishing electrical condition, means including a circuit for operating each movable element, common stopping means controlled over said movable element and said electrically distinguished fixed element for interrupting said operating circuit to stop said movable element, and mechanism for associating said stopping means with an idle point finder.

In witness whereof, we hereunto subscribe 0ur7names this 5th day of December A. D, 191

ALBEN E. LUNDELL. EDGAR H. CLARK. 

